In a photolithography process for manufacturing a semiconductor device, various processing solutions such as resist are supplied to a surface of a semiconductor wafer (hereinafter, simply referred to as “wafer”) which is used as a substrate. A coating and developing apparatus for performing the photolithography process includes a liquid processing apparatus for supplying the various processing solutions.
As an example liquid processing apparatus, there is known a resist coating apparatus. The resist coating apparatus includes a coating processing unit for coating, for example, resist. By way of example, the coating processing unit includes a holding unit for holding the wafer or a cup surrounding a periphery of the wafer held by the holding unit so as to prevent dispersion of the resist.
In order to improve throughput, a multiple number of coating processing units are provided in the resist coating apparatus, and the respective coating processing units are capable of processing wafers at the same time. Further, in order to reduce cost and space, the multiple number of coating processing units may share a common nozzle for supplying the resist. In such a case, the nozzle supported at an arm may move above horizontally arranged cups in an arrangement direction of the cups, and may supply the resist onto the wafers in the respective cups. By way of example, such a resist coating processing unit is described in Patent Document 1.
Recently, as semiconductor devices are diversified, various kinds of resists are used. For the reason, a multiple number of nozzles for supplying the different kinds of resists may be arranged at the arm, and the respective nozzles may be moved together. With this configuration, however, in order to carry out maintenance of a single nozzle, all nozzles need to be moved into a standby section outside the coating processing unit and processing of all wafers need to be stopped. Thus, there has been a demand for improving throughput by making it possible to carry out maintenance of one nozzle while processing wafers by other nozzles.
Described in Patent Document 2 is a liquid processing apparatus including a guide extending in an arrangement direction of a multiple number of cups; a nozzle standby section having a base member moved in a lengthwise direction of the guide and a multiple number of nozzles; and an arm moving forwardly and backwardly in a direction orthogonal to a moving direction of the base member. In this liquid processing apparatus, the base member and the nozzle standby section are guided and moved to the front of each cup. Then, after the nozzles are lifted and moved to above the cup by a leading end portion of the arm, a liquid process is performed. In order to move the nozzle standby section and the base member to the front of the cups, however, the guide needs to be located in front of the multiple number of cups. Thus, an installation space of the apparatus becomes increased.
Furthermore, in Patent Document 1, three cups are arranged in a straight line. When a wafer is processed, a processing nozzle is moved from above a cup to above another cup via above an intermediate cup. When the processing nozzle is moved above the intermediate cup, however, there is a possibility that a processing solution may drop from the processing nozzle onto the wafer. As a result, a defect may occur and a production yield may be reduced.    Patent Document 1: Japanese Patent Laid-open Publication No. 2010-045185    Patent Document 2: Japanese Patent Laid-open Publication No. 2010-34210 (FIGS. 1 and 8)